Modern industrial, commercial, aerospace and military systems depend critically on reliable pumps for fluid handling. Both gas and liquid fluids take advantage of smaller, more distributed and more portable systems for increasing uses in instrumentation and control.
Although important advances in pump technology have been made in the past few decades, progress has been slowed down considerably in the ability to reduce pump size, weight, power consumption and cost. There remains a large gap between the technology for conventional pumps, including micropumps, and more advanced pumps based on microelectronics technology.
The pumping range of micropumps is from about one to tens of microliters per minute. Thus they are useful for applications such as implantable systems for drug delivery or micro dosage for chemical analysis systems. However, pump speeds are still too slow for use in sampling applications. Pressure sensing can at times require rapid reports of any change in pressure, particularly to anticipate a major change in pressure before it fully takes place.
An improved electrostatic pump has been developed, as described in U.S. Pat. No. 6,179,586. In this patent, the pump consists of a single molded plastic chamber with two thin diaphragms staked directly on top of each other. The diaphragms are actuated, depending on design, with electrostatic, electromagnetic or piezoelectric methods. This patent describes the use of a single chamber for pumping.
It is also desirable, if possible, to use technology of this type for valves that regulate flow from various pumps and fluid flow systems. Valves can be used to control the flow or absence of flow from electrostatic pumps.
It would be of great advantage if a valve using conventional mesopump construction could be provided.
Another advantage would be if a valve using conventional mesopump construction could be made from inexpensive parts.
Yet another advantage would be if a value could be designed that would operate as a safety valve or a check valve.
Other advantages and features will appear hereinafter.